Class CollationKey

A CollationKey represents a String under the
rules of a specific Collator object. Comparing two
CollationKeys returns the relative order of the
Strings they represent. Using CollationKeys
to compare Strings is generally faster than using
Collator.compare. Thus, when the Strings
must be compared multiple times, for example when sorting a list
of Strings. It's more efficient to use CollationKeys.

You can not create CollationKeys directly. Rather,
generate them by calling Collator.getCollationKey.
You can only compare CollationKeys generated from
the same Collator object.

Generating a CollationKey for a String
involves examining the entire String
and converting it to series of bits that can be compared bitwise. This
allows fast comparisons once the keys are generated. The cost of generating
keys is recouped in faster comparisons when Strings need
to be compared many times. On the other hand, the result of a comparison
is often determined by the first couple of characters of each String.
Collator.compare examines only as many characters as it needs which
allows it to be faster when doing single comparisons.

The following example shows how CollationKeys might be used
to sort a list of Strings.

Method Detail

compareTo

Compare this CollationKey to the target CollationKey. The collation rules of the
Collator object which created these keys are applied. Note:
CollationKeys created by different Collators can not be compared.

getSourceString

toByteArray

public abstract byte[] toByteArray()

Converts the CollationKey to a sequence of bits. If two CollationKeys
could be legitimately compared, then one could compare the byte arrays
for each of those keys to obtain the same result. Byte arrays are
organized most significant byte first.